Method of manufacture of a nut and tail assembly

ABSTRACT

A nut and tail assembly and method of manufacture including a nut having a first end and an inward flange at the other end, a longitudinal cylindrical hollow body having a first end and a second end at which is located an outstanding flange and a circular longitudinal sleeve. The sleeve extends along said sliding surface and has a flange at a first end abutting against the body flange. A stop is located between the ends of the body and defines a cavity sliding surface generally parallel to the longitudinal body between the stop and flange. The nut inward flange extends into the body cavity and is of large enough diameter to be able to slide on said body sliding surface, but small enough to be held within said cavity defined between said stop and sleeve flange. Projections on the sleeve flange assist in locating the sleeve relative to the nut during the moulding process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/494,496 filed May 4, 2004, that claimed priority from PatentCooperation Treaty Application No. PCT/AU03/00651, which had aninternational filing date of May 29, 2003; which in turn claimedpriority from Australian Application Serial No. PS 2671, which was filedMay 31, 2002; the entire specifications of these aforementionedapplications being expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a pipe or conduit assembly or fittingincluding an outer member rotatable over an inner member, said innermember including a rigid outer sleeve extending over a part of said tailassembly, and to a method of production thereof including any dies forthe production of such a fitting.

2. Background Information

Nut and tail assemblies are typically moulded from plastics material,the typical assembly including a tail having an external thread at oneend and an outstanding flange or lip at the other end with a stemextending therein between, said assembly also including a nut having aninturned flange that bears against the back of the tail outstandingflange and is arranged to firmly retain the assembly to a male threadedfitting. These fittings can be made many ways such as spin-welding ortwo-part operations. Other conduit fittings such as barrel unions, andfittings on the ends of valves can be made by the same methods.

In a previous patent by the same applicant, Australian Patent 579,134(filed as, Serial No. AU198538626), the contents of which are expresslyincorporated by reference herein, there was disclosed both a method anda fitting manufactured by said method that greatly simplified theconstruction of such a fitting having a nut and tail of moulded plasticsmaterial. The method included placing the nut in a die and moulding thetail with the nut in one single die operation so that the tailoutstanding flange was moulded within the body of the nut, the nutinturned flange located behind the outstanding flange of the tail. Sucha method and fitting greatly simplified the then known manufacturingprocesses.

Although the fitting described in the aforementioned patent has beenfound to work satisfactorily in most circumstances, it has been foundthat lateral twisting and bending of such a fitting can cause failure inthe fitting, especially in the body of the tail or stem immediatelyadjacent the inturned flange of the nut. In situations where such afitting may be prone to lateral forces, this type of fitting istherefore unsuitable.

It is an object of the present invention to propose improvements in sucha fitting and construction thereof whereby there is proposed a fittinghaving a nut, a tail of moulded plastics material, a sleeve extending atleast partially over said tail and formed of a resilient material.

It is a further object of the present invention to provide forimprovements in the construction of such a fitting or at least providethe public with a useful alternative.

SUMMARY OF THE INVENTION

Therefore in one form of the invention there is proposed a nut and tailassembly including:

a longitudinal cylindrical hollow body having a first end, said bodyincluding an outwardly extending stop located inwardly from said firstend, said body further having an outstanding flange at the second endthereof, said stop and flange defining therein between a cavity slidingsurface generally parallel to the longitudinal body;

a circular longitudinal sleeve extending along said sliding surface;

a nut having a first end, and an inward flange at the other end, saidnut inward flange extending into said body cavity and being of adiameter to be able to slide on said body sliding surface.

In a further form of the invention, there is proposed a nut and tailassembly including:

a longitudinal cylindrical hollow body having a first end, said bodyincluding an outwardly extending stop located inwardly from said firstend, said body further having an outstanding flange at the second endthereof, said stop and flange defining therein between a cavity slidingsurface generally parallel to the longitudinal body;

a circular longitudinal sleeve extending along said sliding surface andhaving a flange at a first end thereof, said flange abutting againstsaid body flange;

a nut having a first end, and an inward flange at the other end, saidnut inward flange extending into said body cavity and being of adiameter to be able to slide on said body sliding surface.

In preference said body first end includes a plurality of externalthreads. Of course, other types of connections include snap-on typefitting could well be employed.

Preferably said nut includes a plurality of internal threads at saidfirst end.

In preference, said sleeve other end extends into said body. It istherefore anchored into the body and is integral with the body.

In preference, said sleeve other end includes at least one groovewherein said groove assists in longitudinally anchoring said sleeve insaid body.

In preference said body is manufactured from polymeric plastic. Thisenables it to be moulded in a die operation.

In preference said sleeve is manufactured from metal. This may includevarious metals such as brass that then give the fitting strength againstbending and twisting.

In preference said sleeve includes projections extending longitudinallyoutwardly from said flange. These projections help locate the sleevebefore moulding.

In preference said projections are located symmetrically andcircumferentially on said flange.

In preference there are at least four said projections. Theseprojections may be small pin-like projections although they may equallywell be blocks.

Preferably located in between said sleeve and said external threads, isa torque converter to assist in controlling the rotational motion of thebody including said tail and sleeve.

In preference the assembly includes a gasket housed within said nut andabutting against said body outstanding flange.

In yet a further form of the invention there is proposed a method ofmanufacture of a fitting with an inner member having a sleeve, and anouter member that is rotatable over said sleeve, the method includingthe steps of:

-   (a) making the outer members to a shape that includes a radially    inturned annular flange at one end and an axially extending portion    having an internal thread,-   (b) placing a sleeve within said outer member, said sleeve having a    radial outwardly extending annular flange, said sleeve flange    abutting against said outer member flange and extending    longitudinally away from said internal thread,-   (c) positioning the outer member and sleeve onto an axially aligned    male portion of a moulding die and within two female portions, said    male portion including a plurality of locating pins engaging said    sleeve,-   (d) closing the moulding die thereby placing the outer member and    sleeve in their final position and establishing a moulding cavity    within which is located the outer member and sleeve, part of the    surface of said cavity defined by the outer surface of the sleeve    annular flange, part of which is defined by the sleeve inner    surface, part of which is defined by inner surfaces of the female    die portions, and part of which is defined by surfaces of the male    die portions.

In preference the method of manufacture includes making the outer memberby moulding or machining operations.

In preference in the method of manufacture, the moulding cavity is soshaped that the length of the inner member not adjacent the sleeveflange is longer to allow for shrinkage of the inner member duringcooling.

In a still further form of the invention, there is proposed a die formoulding of the tail of a nut and tail assembly having a sleeve, saiddie including two separable complementary female die portions havinginner surfaces defining a recess, and at least one male die portioncharacterized in that the die moulding cavity is defined partly by theouter surface of the annular flange of said sleeve when inserted intosaid recess, partly by the recess surfaces of the female die members,partly by the inner surface of said sleeve, and partly by a surface ofthe male die portion.

In a yet further form of the invention there is proposed a fluidconnector including:

a longitudinal hollow body having a first connection means at one endthereof, an outward flange at the other end thereof, and a stop locatedin between said ends;

a cylindrical sleeve located on top of said body between said outwardflange and said stop; the diameter of said outward flange and said stopbeing greater than the diameter of the body between the two;

a nut having a second connection means at one end and a radiallyextending inward flange at the other end, said inward flange locatedbetween and of a smaller diameter than said body stop and outwardflange.

In preference said nut inward flange diameter is only slightly largerthan the diameter of the sleeve enabling said nut to slide along saidsleeve.

In preference said first connection means are external threads and saidsecond connection means are internal threads.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several implementations of theinvention, and, together with the description, serve to explain theadvantages and principles of the invention.

In the drawings:

FIG. 1 is a perspective view of a moulded fitting embodying the presentinvention and including a nut, tail and sleeve;

FIG. 2 is a perspective view of the sleeve of FIG. 1;

FIG. 3 is a cross-sectional view of the moulded fitting of FIG. 1embodying the present invention;

FIG. 4 is a longitudinal cross-sectional view illustrating the die usedin the manufacture of the fitting or conduit;

FIG. 5 is a cross-sectional view of a moulded fitting having analternate configuration of a sleeve, according to the present invention;

FIG. 6 is a perspective view of a sleeve having yet a further alternateconfiguration and including integrally formed locating projections;

FIG. 7 (a) is a partial cross-sectional view of the sleeve, nut and tailof FIG. 5 before the moulded plastic has cooled; and

FIG. 7 (b) is a partial cross-sectional view as in FIG. 7(a) but whenthe moulded plastic has cooled causing shrinkage of the plastic.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of the invention refers to theaccompanying drawings. Although the description includes exemplaryembodiments, other embodiments are possible, and changes may be made tothe embodiments described without departing from the spirit and scope ofthe invention. Wherever possible, the same reference numbers will beused throughout the drawings and the following description to refer tothe same and like parts.

Referring to the Figures there is shown a fitting 10 including a nut 12,tail 14, and a sleeve 16. Nut 12 includes a body 18 having internalthreads 20, bore 22 at one end, and a radially inturned flange 24 at theother end. The internal threads 20 are adapted to engage externalthreads of a suitable device such as a water meter or similar device. AnO-ring, washer, or gasket 26 is used within the nut 12 for sealingengagement with such device.

The outer surface of the nut 12 is of a non-circular shape 28 to enablea tool, such as a wrench, to be used to tighten the nut 12 uponapplication.

The tail 14 includes a longitudinal body 30 having external threads 32at one end thereof, an outwardly extending integrally formed torqueconverter 34 having a polygonal outer surface 36 assisting engagement ofthe converter 34 with an appropriate tool such as a wrench (not shown)that can be used to rotate the tail 14.

The tail 14 includes a stem 38 extending from the torque converter 34longitudinally away from the external threads 32 and having an outwardlyextending radial flange 40. The flange 40 may include a shoulder (notshown) for retention of the gasket 26.

The sleeve 16 extends along the outer surface 42 of the tail 30 betweenthe torque converter 34 and the flange 40, the sleeve 16 at one endincluding radially outward flange 44 that is correspondingly shaped tonestle in flange 40 of the tail stem 38. The other end of the sleeve 16extends into the tail body 30 under the torque converter 34.

The diameters of the stem 38, sleeve 16, and the nut flange 24 arechosen so that the nut 12 can freely slide alongside the sleeve 16. Thatis, the inner diameter of the nut flange 24 is greater than the outerdiameter of the sleeve 16. At the same time, the outer diameter of theoutward flange 44 is greater than the inner diameter of the nut flange40 so that the nut 12 remains captured and can slide alongside the stem16 between the torque converter inner surface 46 and the inner surface48 of the outward flange 44 of the sleeve 16.

In the method of manufacture of the nut and tail assembly 10, locationpins 50 are used to hold the sleeve 16 in place before moulding tothereby lock the sleeve 16 in position on the stem 38 with the sleeve 16partially extending into the tail 30. As illustrated in FIG. 1, fourpins 50 may be used, although it is to be understood that more or lessmay be used depending on the size of the sleeve and the assembly. It isto be understood that the pins 50 may be integral with the sleeve 16,although they are typically part of the die arrangement. If part of thedie arrangement, as the pins are removed, small apertures are left inthe flange 40 of the stem 38.

FIG. 4 illustrates a die 52 that is used in the method of manufacture ofthe nut and tail assembly 10 according to the present invention. The die52 is provided with four parts, a front male portion 54, a rear maleportion 56 that, upon die closure, abuts the front male portion 54, andtwo female portions 58 and 60 which, upon closure, abut each other on anaxial plane 62.

When the female portions 58 and 60 are closed they define a cavity orrecess 64.

In the manufacture of assembly 10, however, sleeve 16 is firstlyinserted into nut 12 so that flanges 40 and 44 abut against each other.The nut 12, with the sleeve 16 extending outwardly is then positioned inthe front male portion 54 of the die 52 that includes locating pins 50.The locating pins 50 are advantageous for a number of reasons. Firstly,they ensure that the sleeve longitudinal axis is generally parallel tothe axis 62. They also ensure that during the moulding operation the nutflange 24 abuts the sleeve flange 44 so that the determined thickness ofthe moulded plastic on the sleeve flange 44 is achieved. Otherwise, ifthe sleeve 16 were to move axially toward the nut flange 24 during themoulding operation this thickness may be reduced leading to anunacceptable assembly where the sleeve is not supported within the tail30.

When the female portions 58 and 60 are then closed they bear against theouter surfaces of the nut 12 and a portion of the sleeve 16 establishinga moulding cavity 66. The moulding cavity 66 is therefore defined by thesurface or boundary of recess 64, partially by the front and rear maleportions 54 and 56 adjacent their mutual abutment zone, partiallydefined by the inner surface of the annular nut flange 24 and partiallydefined by the sleeve 16.

The die 52 is typically formed from tool steel and is provided withcooling conduits 68 therein. The die cavity, in which the tail formsflange 40, may have an additional shoulder recess (not shown) forretention of a sealing ring, typically an O-ring (not shown). In thecase of an O-ring, the tail may also include an overhang to capture theO-ring in position (not shown).

Fluent plastics material is injected into the die cavity 66. However,the nut 12 is cold, and the die portions are rapidly cooled by thecooling effect of the fluid flowing through the conduits 68. The dieportions are then separated, and the nut 12 and the sleeve 16 remaincaptive on the front end of the tail 14 due to the outstanding flangeportions 24 and 44 of the nut 12 and sleeve 16 and the outstandingflange portion 40 of the nut stem 38 that, by its moulding, is of acomplementary shape to the inner surface of the nut and sleeve flange 24and 44. The sleeve 16 is also captive since its other end, which is theend opposite to its flange, is now captured within the stem 38 of thetail 30.

It will now be readily apparent to the reader that the present inventionensures that there is provided a nut and tail assembly that has a sleevethat improves upon the integral strength of the assembly. Further, theprocess of manufacture that includes the pins ensures that the assemblycan be repeatedly made whilst ensuring quality standards.

The sleeve is typically made from metal such as brass that has thenecessary strength to provide for support of the rest of the fitting.

In an alternative embodiment of the present invention and as illustratedin FIG. 5 is an assembly including sleeve 16, the sleeve at its outerend opposite to flange 44 including annular grooves 70. These grooves 70located at the end of the sleeve opposite to the flange 44 are embeddedwithin the stem 38 of the tail 14. During the moulding operation, thegrooves 70 are filled with plastic that, when cools, integrally locksthe sleeve 16 to the stem 38 thereby providing additional supportagainst longitudinal movement between the two. Of course, instead ofgrooves, the sleeve may very well have projections around which formsthe body during moulding.

In the embodiment discussed so far, locating pins 50 were positioned onthe die. However, not only do the locating features not need be pins,but they may in fact be projections that are integrally formed in thesleeve 16.

Illustrated in FIG. 6 is such an arrangement where locating blocksprojections or blocks 74 are part of the sleeve 16. This may occur, forexample, where one is using suitably strong plastic material, notnecessarily metal, the sleeve 16 also being able to be produced as partof the moulding operation.

One of the problems often encountered in moulding plastics is shrinkage.Where the plastic shrinks in one direction and does not encounter anyresistance, only its size is reduced. However, the addition of a sleeveresults in the plastic encountering resistance when shrinking in thelongitudinal direction of the stem. For that reason, it is advantageousto construct a die so that when the plastic is still hot, the innerdiameter of the stem 74 projects further outwardly into the nut 12 thanthe flange 40, as shown in FIG. 7(a). As the plastic cools, this portion74 of the stem 38 retracts into the tail 30 whilst the flange 40 of thetail 30 is prevented from retracting due to the sleeve flange 44. Sincethe amount of shrinkage can be predetermined, moulding a tail whoseshape whilst hot is as in FIG. 7(a) can result in the cooled shape beingas illustrated in FIG. 7(b).

Those skilled in the art will now appreciate that the nut 12 canslidably move alongside the outer surface 42 of the sleeve 16. Thesleeve 16 is typically made from metal such as brass, thereby providingstrength to the assembly against any lateral forces.

It has been found that there is no tendency for adhesion or fusion tooccur between the surfaces of the nut, sleeve, and tail, and uponshrinkage of the tail under cooling, the nut has been found to be freelyrotatable about the tail. Since the surfaces are generally circular,there is very good surface to surface contact as the nut is tightenedwhen in use.

It is to be understood that reference to flange through the descriptiontypically includes an annular flange.

The present invention provides a nut and tail assembly that having aresilient sleeve, provides an assembly that withstands lateral forceswhilst being manufacturable without expensive weld and inspectionoperations, at the same time reducing overall cost.

Further advantages and improvements may very well be made to the presentinvention without deviating from its scope. Although the invention hasbeen shown and described in what is conceived to be the most practicaland preferred embodiment, it is recognized that departures may be madetherefrom within the scope and spirit of the invention, which is not tobe limited to the details disclosed herein, but is to be accorded thefull scope of the claims so as to embrace any and all equivalent devicesand apparatus.

1. A method of manufacture of a fitting with an inner member having asleeve and an outer member that is rotatable over said sleeve, themethod including the steps of: a) making the outer member to a shapethat includes a radially inturned annular flange at one end and anaxially extending portion having an internal thread, b) placing a sleevewithin said outer member, said sleeve having a radial outwardlyextending annular flange, said sleeve flange abutting against said outermember flange and extending longitudinally away from said internalthread, c) positioning the outer member and sleeve onto an axiallyaligned male portion of the moulding die and within two female portions;said male portions including a plurality of locating pins engaging saidsleeve; d) closing the moulding die thereby placing the outer member andsleeve in their final position and establishing a moulding cavity withinwhich is located the outer member and sleeve, part of the surface ofsaid cavity defined by the outer surface of the sleeve annular flange,part of which is defined by the sleeve inner surface, part of which isdefined by inner surfaces of the female die portions, and part of whichis defined by surfaces of the male die portions.
 2. The method ofmanufacture of a fitting as defined in claim 1, further comprising thesteps of: e) injecting a fluent plastics material in the mouldingcavity; and f) cooling the plastics material.
 3. A method of manufactureof a fitting as in claim 1, wherein making the outer member includes atleast one of moulding and machining operations.
 4. A method ofmanufacture of a fitting as in claim 1, wherein the moulding cavity isso shaped that the length of the inner member not adjacent said sleeveflange is longer to allow for shrinkage of the inner member duringcooling.
 5. A method of manufacture of a fitting with an inner memberhaving a sleeve and an outer member that is rotatable over said sleeve,the method including the steps of: a) making the outer member to a shapethat includes a radially inturned annular flange at one end and anaxially extending portion having an internal thread, b) placing a sleevewithin said outer member, said sleeve having a radial outwardlyextending annular flange, and having one or more locating projectionsextending outwardly away from said annular flange in a directionparallel to a longitudinal axis of the sleeve; c) abutting the one ormore projections on the flange of the sleeve against said outer memberflange; such that said sleeve extends longitudinally away from saidinternal thread; d) positioning the outer member and sleeve onto anaxially aligned male portion of a moulding die and within two femaleportions thereof; e) maintaining the relative positions of the outermember and the sleeve by way of the one or more locating projections; f)closing the moulding die thereby placing the outer member and sleeve intheir final position and establishing a moulding cavity within which islocated the outer member and sleeve, part of the surface of said cavitydefined by the outer surface of the sleeve annular flange, part of whichis defined by the sleeve inner surface, part of which is defined byinner surfaces of the female die portions, and part of which is definedby surfaces of the male die portions.
 6. The method of manufacturing asdefined in claim 5, further comprising the step of: g) injecting fluentplastics material into the moulding cavity; and h) cooling the injectedplastics material.
 7. A method of manufacture of a fitting as in claim5, wherein making the outer member includes at least one of moulding andmachining operations.
 8. The method of manufacture of a fitting as inclaim 7, wherein the step of placing a sleeve within said outer memberincludes the step of selecting a sleeve manufactured from a metal.
 9. Amethod of manufacture of a fitting as in claim 5, wherein the mouldingcavity is so shaped that the length of the inner member not adjacentsaid sleeve flange is longer to allow for shrinkage of the inner memberduring cooling.
 10. The method of manufacturing as defined in claim 5,wherein the step of placing the sleeve on the outer member includesutilizing a sleeve which includes a plurality of annular grooves formedat an end opposite to the radial outwardly extending annular flange. 11.The method of manufacturing as defined in claim 6, whereby the step ofinjecting fluent plastics material into the moulding cavity causes theannular grooves to be filled with plastic, thereby embedding at least aportion of the sleeve into the moulded fitting.
 12. A die for mouldingof the tail of a nut and tail assembly having a sleeve, said dieincluding two separable complementary female die portions having innersurfaces defining a recess, and at least one male die portioncharacterized in that the die moulding cavity is defined partly by theouter surface of the annular flange of said sleeve when inserted intosaid recess, partly by the recess surfaces of the female die members,partly by the inner surface of said sleeve, and partly by a surface ofthe male die portion.
 13. The die as defined in claim 12, wherein themale die portion includes one or more projections for spacing componentsretained within the die.
 14. The die as defined in claim 13, wherein theone or more projections are locating pins.
 15. The die as defined inclaim 14, wherein the male die portion includes four locating pins. 16.The die as defined in claim 12, wherein the annular flange of the sleeveincludes one or more projections for spacing components retained withinthe die.
 17. The die as defined in claim 16, wherein the one or moreprojections are locating pins.
 18. The die as defined in claim 17,wherein the annular flange includes four locating pins.